The CCTV footage showed a frail old man walking unsteadily along the street he’d lived in for more than 50 years. For anyone who has a loved one with dementia, this grainy image of 82-year-old Archie Campbell was heart breaking, because it was the last time Archie, who has dementia, had been seen since going missing from home.

Last night’s episode of BBC1’s documentary series Reported Missing featured the three- day police hunt to find him. It was not easy viewing. ‘At this point, we’re looking for a body,’ one of the police officers involved in the search admitted. By then, Archie had been missing for more than 55 hours without a single confirmed sighting and this worst case scenario was fast becoming a very real possibility. After all, how on earth could an elderly man survive such an ordeal?

Visitors to Unforgettable would have been impressed by Durham Constabulary’s thorough land and air investigation, including helicopter searches and radio and TV news appeals. At one point, almost every officer in the county was involved, alongside many volunteers. The police officers understanding of dementia was also heartening. Archie was, they discovered, a former paratrooper who’d served in the army for 30 years. ‘He may have reverted back to his paratrooper days when it wouldn’t have been unusual for him to walk 20 miles a day,’ one officer said, as the search area was widened to include dense woodland and a fast running river...

The search took on an added poignancy when it was revealed that Archie’s wife Pat had died only two months earlier…from dementia. They’d been married for 50 years and, when she’d finally gone into a care home, Archie visited three times a day, without fail.

Although grief-stricken, Archie had remained fiercely independent, and his family were left with the same dilemma many others face; how to respect their father’s wishes whilst also keeping him safe. ‘Maybe he is too frail to be out walking on his own, but to take his walks away would have been the end for him,’ his niece said. ‘We’ve already taken Pat away, to take the walks as well would have been too sad for him.’

Watching Archie’s family endured three endless days and nights of worry was hard enough, it also made sense of the growing popularity of GPS tracking devices for people with dementia. (For who would choose to risk such an ordeal, if they can find a way to avoid it). But perhaps the most uncomfortable part of this investigation was the way in which it seemed to focus a little too much on Archie’s son Peter, the person who’d first alerted police t that his dad was missing.

Peter’s astonishment when officers started to search his home (and even his attic) was obvious. But it was only after a lengthy interview with detectives that police decided they had ‘no concerns’ about him or any of Archie’s family. What a relief that must have been.

Of course, we understand they had to explore every avenue, (and would have faced enormous flack if they hadn’t) but we doubt this would have made the experience any easier for Archie’s eldest son.

And, in retrospect, perhaps they should have trusted Peter’s instinct a little more. When asked early on where he thought his dad might be, he replied; ‘I honestly believe he’s gone for a walk and he’s fallen.’

It turned out, he was right.

Overall, the time and effort that went into finding Archie was deeply impressive. The cost must have been enormous (the police helicopter alone costs £1500 per hour and it was used a lot). The joy of finding him alive was extraordinarily moving for everyone involved, including viewers.

Though the search for Archie did, thankfully, end on a positive note, the experience did have one long lasting and rather sad implication. For whilst found alive, Archie was not able to return to his home or his independent life. After spending two weeks in hospital he moved into a care home. ‘In an ideal world I’d like my dad back at home, but it’s obvious to everyone he can’t,’ Peter explains.

We’re sure families living with dementia will understand and sympathise with Peter, and we hope that Archie remains happy in his new home. But if we are to learn anything from Archie’s ordeal - and from such a thought-provoking documentary - it should be that GPS tracking devices are no longer considered a luxury item for people with dementia. They are, it would seem, a necessity.